How does this normal map create surface imperfections instead of elevations/bumps?
You can bake textures like this in Blender. After setting up all the components of the shader you want to bake in the Shader Editor:

1 - Create a new image in the UV Editor

2 - Add an Image Texture in your Shader Editor and select the image you created in step 1 as the image being referenced

3, 4, 5 -  In your Render Properties tab, select Cycles, select your Bake Type (Normal in your case), and hit the Bake button

6 - A normal map will be generated consolidating all normal elements present in your shader as the image in your UV Editor